Answer:
v = 10 [m/s]
Explanation:
The largest mass is that of 4 [kg], in this way the momentum can be calculated by means of the product of the mass by velocity.
where:
P = momentum [kg*m/s]
m = mass = 4 [kg]
v = velocity = 5 [m/s]
Now the momentum:
![P=4*5\\P=20[kg*m/s]](https://tex.z-dn.net/?f=P%3D4%2A5%5C%5CP%3D20%5Bkg%2Am%2Fs%5D)
This same momentum is equal for the other mass, in this way we can find the velocity.
![P=m*v\\20=2*v\\v=10[m/s]](https://tex.z-dn.net/?f=P%3Dm%2Av%5C%5C20%3D2%2Av%5C%5Cv%3D10%5Bm%2Fs%5D)
Answer:a) 34.5 N; b) 24.5 N; c) 10 N; d) 1J
Explanation: In order to solve this problem we have to used the second Newton law given by:
∑F= m*a
F-f=m*a where f is the friction force (uk*Normal), from this we have
F= m*a+f=5 Kg*2 m/s^2+0.5*5Kg*9.8 m/s^2= 34.5 N
then f=uk*N=0.5*5Kg*9.8 m/s^2= 24.5N
the net Force = (34.5-24.5)N= 10 N
Finally the work done by the net force is equal to kinetic energy change so
W=∫Force net*dr= 10 N* 0.1 m= 1J
Balancing.
When the same force is applied from both sides,the forces cancel out each other.
